of/fdt: Rework early_init_dt_scan_memory() to call directly

Use of the of_scan_flat_dt() function predates libfdt and is discouraged
as libfdt provides a nicer set of APIs. Rework
early_init_dt_scan_memory() to be called directly and use libfdt.

Cc: John Crispin <john@phrozen.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211215150102.1303588-1-robh@kernel.org

1 files changed, 10 insertions, 11 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 6e1a106f02eb..ad1230c4f3fe 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -532,19 +532,18 @@ static int  __init early_init_drmem_lmb(struct drmem_lmb *lmb,
 }
 #endif /* CONFIG_PPC_PSERIES */
 
-static int __init early_init_dt_scan_memory_ppc(unsigned long node,
-						const char *uname,
-						int depth, void *data)
+static int __init early_init_dt_scan_memory_ppc(void)
 {
 #ifdef CONFIG_PPC_PSERIES
-	if (depth == 1 &&
-	    strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0) {
+	const void *fdt = initial_boot_params;
+	int node = fdt_path_offset(fdt, "/ibm,dynamic-reconfiguration-memory");
+
+	if (node > 0)
 		walk_drmem_lmbs_early(node, NULL, early_init_drmem_lmb);
-		return 0;
-	}
+
 #endif
-	
-	return early_init_dt_scan_memory(node, uname, depth, data);
+
+	return early_init_dt_scan_memory();
 }
 
 /*
@@ -749,7 +748,7 @@ void __init early_init_devtree(void *params)
 
 	/* Scan memory nodes and rebuild MEMBLOCKs */
 	early_init_dt_scan_root();
-	of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
+	early_init_dt_scan_memory_ppc();
 
 	parse_early_param();
 
@@ -858,7 +857,7 @@ void __init early_get_first_memblock_info(void *params, phys_addr_t *size)
 	 */
 	add_mem_to_memblock = 0;
 	early_init_dt_scan_root();
-	of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
+	early_init_dt_scan_memory_ppc();
 	add_mem_to_memblock = 1;
 
 	if (size)